Commit b2ce2643 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

blk-throttle: clean up blkg_policy_data alloc/init/exit/free methods 



With the recent addition of alloc and free methods, things became
messier.  This patch reorganizes them according to the followings.

* ->pd_alloc_fn()

  Responsible for allocation and static initializations - the ones
  which can be done independent of where the pd might be attached.

* ->pd_init_fn()

  Initializations which require the knowledge of where the pd is
  attached.

* ->pd_free_fn()

  The counter part of pd_alloc_fn().  Static de-init and freeing.

This leaves ->pd_exit_fn() without any users.  Removed.

While at it, collapse an one liner function throtl_pd_exit(), which
has only one user, into its user.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 4fb72036

block/blk-cgroup.c

+0 −11
Original line number Diff line number Diff line
@@ -402,15 +402,6 @@ static void blkg_destroy_all(struct request_queue *q) 
void __blkg_release_rcu(struct rcu_head *rcu_head)

{

	struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head);

	int i;



	/* tell policies that this one is being freed */

	for (i = 0; i < BLKCG_MAX_POLS; i++) {

		struct blkcg_policy *pol = blkcg_policy[i];



		if (blkg->pd[i] && pol->pd_exit_fn)

			pol->pd_exit_fn(blkg);

	}



	/* release the blkcg and parent blkg refs this blkg has been holding */

	css_put(&blkg->blkcg->css);
@@ -1127,8 +1118,6 @@ void blkcg_deactivate_policy(struct request_queue *q, 


		if (pol->pd_offline_fn)

			pol->pd_offline_fn(blkg);

		if (pol->pd_exit_fn)

			pol->pd_exit_fn(blkg);



		if (blkg->pd[pol->plid]) {

			pol->pd_free_fn(blkg->pd[pol->plid]);

block/blk-throttle.c

+20 −37
Original line number Diff line number Diff line
@@ -330,26 +330,19 @@ static struct bio *throtl_pop_queued(struct list_head *queued, 
}



/* init a service_queue, assumes the caller zeroed it */

static void throtl_service_queue_init(struct throtl_service_queue *sq,

				      struct throtl_service_queue *parent_sq)

static void throtl_service_queue_init(struct throtl_service_queue *sq)

{

	INIT_LIST_HEAD(&sq->queued[0]);

	INIT_LIST_HEAD(&sq->queued[1]);

	sq->pending_tree = RB_ROOT;

	sq->parent_sq = parent_sq;

	setup_timer(&sq->pending_timer, throtl_pending_timer_fn,

		    (unsigned long)sq);

}



static void throtl_service_queue_exit(struct throtl_service_queue *sq)

{

	del_timer_sync(&sq->pending_timer);

}



static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)

{

	struct throtl_grp *tg;

	int cpu;

	int rw, cpu;



	tg = kzalloc_node(sizeof(*tg), gfp, node);

	if (!tg)
@@ -361,6 +354,19 @@ static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node) 
		return NULL;

	}



	throtl_service_queue_init(&tg->service_queue);



	for (rw = READ; rw <= WRITE; rw++) {

		throtl_qnode_init(&tg->qnode_on_self[rw], tg);

		throtl_qnode_init(&tg->qnode_on_parent[rw], tg);

	}



	RB_CLEAR_NODE(&tg->rb_node);

	tg->bps[READ] = -1;

	tg->bps[WRITE] = -1;

	tg->iops[READ] = -1;

	tg->iops[WRITE] = -1;



	for_each_possible_cpu(cpu) {

		struct tg_stats_cpu *stats_cpu = per_cpu_ptr(tg->stats_cpu, cpu);
@@ -375,8 +381,7 @@ static void throtl_pd_init(struct blkcg_gq *blkg) 
{

	struct throtl_grp *tg = blkg_to_tg(blkg);

	struct throtl_data *td = blkg->q->td;

	struct throtl_service_queue *parent_sq;

	int rw;

	struct throtl_service_queue *sq = &tg->service_queue;



	/*

	 * If on the default hierarchy, we switch to properly hierarchical
@@ -391,25 +396,10 @@ static void throtl_pd_init(struct blkcg_gq *blkg) 
	 * Limits of a group don't interact with limits of other groups

	 * regardless of the position of the group in the hierarchy.

	 */

	parent_sq = &td->service_queue;



	sq->parent_sq = &td->service_queue;

	if (cgroup_on_dfl(blkg->blkcg->css.cgroup) && blkg->parent)

		parent_sq = &blkg_to_tg(blkg->parent)->service_queue;



	throtl_service_queue_init(&tg->service_queue, parent_sq);



	for (rw = READ; rw <= WRITE; rw++) {

		throtl_qnode_init(&tg->qnode_on_self[rw], tg);

		throtl_qnode_init(&tg->qnode_on_parent[rw], tg);

	}



	RB_CLEAR_NODE(&tg->rb_node);

		sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue;

	tg->td = td;



	tg->bps[READ] = -1;

	tg->bps[WRITE] = -1;

	tg->iops[READ] = -1;

	tg->iops[WRITE] = -1;

}



/*
@@ -436,17 +426,11 @@ static void throtl_pd_online(struct blkcg_gq *blkg) 
	tg_update_has_rules(blkg_to_tg(blkg));

}



static void throtl_pd_exit(struct blkcg_gq *blkg)

{

	struct throtl_grp *tg = blkg_to_tg(blkg);



	throtl_service_queue_exit(&tg->service_queue);

}



static void throtl_pd_free(struct blkg_policy_data *pd)

{

	struct throtl_grp *tg = pd_to_tg(pd);



	del_timer_sync(&tg->service_queue.pending_timer);

	free_percpu(tg->stats_cpu);

	kfree(tg);

}
@@ -1421,7 +1405,6 @@ static struct blkcg_policy blkcg_policy_throtl = { 
	.pd_alloc_fn		= throtl_pd_alloc,

	.pd_init_fn		= throtl_pd_init,

	.pd_online_fn		= throtl_pd_online,

	.pd_exit_fn		= throtl_pd_exit,

	.pd_free_fn		= throtl_pd_free,

	.pd_reset_stats_fn	= throtl_pd_reset_stats,

};
@@ -1616,7 +1599,7 @@ int blk_throtl_init(struct request_queue *q) 
		return -ENOMEM;



	INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn);

	throtl_service_queue_init(&td->service_queue, NULL);

	throtl_service_queue_init(&td->service_queue);



	q->td = td;

	td->queue = q;

block/cfq-iosched.c

+11 −4
Original line number Diff line number Diff line
@@ -1584,7 +1584,17 @@ static void cfq_cpd_init(const struct blkcg *blkcg) 


static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)

{

	return kzalloc_node(sizeof(struct cfq_group), gfp, node);

	struct cfq_group *cfqg;



	cfqg = kzalloc_node(sizeof(*cfqg), gfp, node);

	if (!cfqg)

		return NULL;



	cfq_init_cfqg_base(cfqg);

	cfqg_stats_init(&cfqg->stats);

	cfqg_stats_init(&cfqg->dead_stats);



	return &cfqg->pd;

}



static void cfq_pd_init(struct blkcg_gq *blkg)
@@ -1592,11 +1602,8 @@ static void cfq_pd_init(struct blkcg_gq *blkg) 
	struct cfq_group *cfqg = blkg_to_cfqg(blkg);

	struct cfq_group_data *cgd = blkcg_to_cfqgd(blkg->blkcg);



	cfq_init_cfqg_base(cfqg);

	cfqg->weight = cgd->weight;

	cfqg->leaf_weight = cgd->leaf_weight;

	cfqg_stats_init(&cfqg->stats);

	cfqg_stats_init(&cfqg->dead_stats);

}



static void cfq_pd_offline(struct blkcg_gq *blkg)

include/linux/blk-cgroup.h

+0 −2
Original line number Diff line number Diff line
@@ -128,7 +128,6 @@ typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node); 
typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);

typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg);

typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg);

typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg);

typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);

typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg);
@@ -145,7 +144,6 @@ struct blkcg_policy { 
	blkcg_pol_init_pd_fn		*pd_init_fn;

	blkcg_pol_online_pd_fn		*pd_online_fn;

	blkcg_pol_offline_pd_fn		*pd_offline_fn;

	blkcg_pol_exit_pd_fn		*pd_exit_fn;

	blkcg_pol_free_pd_fn		*pd_free_fn;

	blkcg_pol_reset_pd_stats_fn	*pd_reset_stats_fn;

};

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